In order to capture infrared (IR) images with a camera, an IR filter and sensor is often implemented along with a visible light (red/green/blue “RGB”) filter and sensor that captures visible light images. The use of a dual band RGBIR filter allows a single camera to be utilized to capture both visible light images and IR images. By using a single camera, size and cost can be saved, as well as avoiding the need to do a geometry calibration that is required when two cameras are utilized.
However, the colors resident in the visible image can be contaminated by the IR energy passing through the IR band of the dual band filter, since RGB pixels also have a spectral response in the IR band. Additionally, the IR image can be contaminated by the visible light energy in a similar manner.
Accordingly, in a camera that has a dual band RGBIR filter, conventional techniques for acquiring a quality RGB image employ a unique image signal processor (ISP), since the pattern of a pixel array on an RGBIR sensor is different than that of a conventional RGB sensor, which produces a conventional RGB “Bayer” pattern. Using an RGBIR sensor, some pixels of a conventional Bayer pattern are replaced by IR pixels. A conventional ISP is not able to perform conventional processing on the resulting image that it receives from an RGBIR sensor.